<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 100%;
            height: 100px;
            background-color: skyblue;
        }
        span{
            width: 100px;
            height: 100px;
            background-color: yellow;
            order: 1;
        }
        em{
            flex:1;
            height: 100px;
            background-color: orange;
            order: 1;
        }
        i{
            flex:1;
            height: 100px;
            background-color: greenyellow;
            order: 1;
        }
    </style>
</head>
<body>
<div class="">
    <span>1</span>
    <em>2</em>
    <i>4</i>
    <span>3</span>
</div>
</body>
</html>